Moonlocket by Peter Bunzl

Storm clouds gather over Lily and Robert’s summer when criminal mastermind the Jack of Diamonds appears. For Jack is searching for the mysterious Moonlocket – but that’s not the only thing he wants.

Suddenly, dark secrets from Robert’s past plunge him into danger. Jack is playing a cruel game that Robert is a part of. Now Lily and Malkin, the mechanical fox, must stay one step ahead before Jack plays his final, deadly card…